JP3043575B2 - Image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus such as a laser printer, and more particularly, to a method for cooling the inside of an image recording apparatus.

[0002]

2. Description of the Related Art Conventionally, an image recording apparatus such as a laser printer is composed of relatively high power consumption parts such as a fixing heater and a motor, and the temperature inside the apparatus rises due to these parts. .

[0003] A cooling means such as a cooling fan is used to suppress the temperature rise in the apparatus. Usually, the apparatus is controlled to rotate at the same time as turning on the power or to rotate at the same time as printing.

[0004]

However, in the above-mentioned conventional example, even when printing a small amount, the cooling fan is always rotating and cooling is performed even when the temperature inside the apparatus is relatively low due to heat generated by the electric components. It was very uneconomical because it generated loud noise and required electric power to rotate the cooling fan.

[0005] In some cases, the temperature inside the apparatus is measured using a thermistor or the like. However, temperature detection is costly and expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide an image recording apparatus capable of reducing the noise of the apparatus main body and efficiently cooling the inside of the apparatus. Is to do.

[0007]

According to the present invention, there is provided an image recording section for recording an image on a sheet material in accordance with an image signal from an image signal forming section, and an apparatus main body. and cooling means for cooling, subjected to the image signal forming section
Current value measuring means for measuring the supplied current value, and the current value
The measured value of the measuring means is compared with a predetermined value to drive the cooling means.
Control means for controlling the image recording apparatus,
The control means determines that the measured value of the current value measuring means is the predetermined value.
After a predetermined time has passed after exceeding the value, the cooling means is driven.
Is started .

[0008]

[0009]

[0010]

[0011]

[Action] configuration image recording apparatus as described above, control
Control means, after the measured value of the current value measuring means exceeds a predetermined value,
After a predetermined time has elapsed, the driving of the cooling means is started.
The driving of the cooling means can be started at an optimal timing.

[0012]

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a reference example will be described.

FIG. 1 is a sectional view showing an image recording apparatus as a reference example .

In FIG. 1, reference numeral 1 denotes a paper feed cassette, and 2 denotes a paper feed roller. The paper feed roller 2 is supplied by a paper feed roller 2 in response to a print start command from an image controller (image signal forming unit, see FIG. 2) to be described later. A recording sheet S as a sheet material in the apparatus is fed into the apparatus. Reference numeral 3 denotes a registration roller that removes the skew of the recording sheet S and conveys the recording sheet S according to a timing signal from an image controller. 4
Denotes an exposure unit for ON / OFF modulating a semiconductor laser according to image data of an image controller. Reference numeral 5 denotes a polygon unit which scans a laser beam emitted from the exposure unit 4 onto a photosensitive drum 7 via a return mirror 6. The periphery of the photosensitive drum 7 is an image recording unit, and the inside of the apparatus is heated together with a fixing roller described later. 8 is 1
In the next charger, the photosensitive drum 7 is primarily charged by a known electrophotographic process. A developing unit 9 develops the electrostatic latent image formed on the photosensitive drum 7 with the toner by the above-described laser beam after the primary charging. A transfer charger 10 transfers the toner image developed on the photosensitive drum 7 to the transported recording paper S. A fixing roller 11 fixes the toner image transferred onto the recording sheet S to the recording sheet S by a roller heated to a predetermined temperature. A paper discharge roller 12 discharges the recording paper S on which the image is fixed by the fixing roller 11 to the outside of the main body. Reference numeral 13 denotes a cooling fan as cooling means, which cools electric components inside the apparatus main body and components related to the electrophotographic process.

FIG. 2 is a control block diagram of the image recording apparatus.

In the figure, 14 is a converter transformer,
Reference numerals 15a and 15b denote rectifier diodes, and reference numeral 16 denotes a smoothing capacitor, which generates a power supply for the image recording apparatus from a primary side commercial power supply (not shown).

17a and 17b are resistors for determining a reference voltage,
Reference numeral 18 denotes a current detection resistor as current value measuring means. 1
Reference numeral 9 denotes a comparator, which compares a reference voltage determined by the resistors 17a and 17b with a voltage value detected by the current flowing through the current detection resistor 18 to detect whether or not a predetermined current has been exceeded.

Reference numeral 20 denotes a CPU which controls the above-described printing process and controls the rotation of the cooling fan 13. Reference numeral 21 denotes an image controller as an image signal forming unit, which generates an image signal based on code data from an external device such as a host computer. The current value supplied to the image controller 21 is detected by the comparator 19, and when it is determined that the current value has exceeded a predetermined value (first predetermined value), the CPU 20 starts the rotation of the cooling fan 13. When the current value falls below a predetermined value (a second predetermined value, which is the same as the first predetermined value in this embodiment ), the rotation of the cooling fan 13 is stopped. The predetermined value can be changed depending on whether the current value rises or falls, but is the same value in the present embodiment .

The setting of the above-mentioned predetermined current is determined based on a relation between the consumption current which is obtained in advance and the temperature rise in the apparatus. this
In the reference example , the drive control of the cooling fan 13 is performed by the current value supplied to the image controller 21 as the image signal forming unit. However, the driving of the image controller 21 and the image controller that increases the temperature in the apparatus are substantially the same. By measuring the value of the current supplied to the image controller 21, the temperature rise in the apparatus can be indirectly detected. Of course, the current value of other components may be used as long as the temperature rise in the apparatus can be detected. With this configuration, it is not necessary to provide a thermistor or the like for measuring the temperature as in the related art.

By performing the above control, the cooling fan 13 is rotated only when cooling is necessary.
Compared with the conventional control, noise is greatly improved, and when the internal temperature is low, the inside of the apparatus can be efficiently cooled without performing cooling.

[0022] (Embodiment) FIG 3 shows the control of the real施例of the present invention. 1 and 2 will be described using the same reference numerals. FIG. 3 shows the relationship between the current value supplied to the image controller 21 and the temperature rise in the apparatus. Image controller 2
When the value of the current supplied to 1 exceeds a predetermined value, the internal temperature of the apparatus rises and reaches a temperature requiring cooling after a first predetermined time (T1 sec). The CPU 20 measures a first predetermined time (T1sec) while observing the current value, and starts the rotation of the cooling fan 13 when judging that the predetermined temperature has been reached. When the current value supplied to the image controller 21 falls below a predetermined value, the temperature inside the apparatus starts to fall, but there is residual heat. Therefore, by continuing the rotation of the cooling fan 13 for a predetermined time (T2 sec), the temperature is rapidly increased. The temperature inside the apparatus can be lowered. Predetermined value of the current value of the above reference
As in the example , the case where the current value increases and the case where the current value decreases may be changed.

As described above, by measuring the predetermined current value and time, it is possible to estimate the rate of increase in the temperature inside the apparatus, and it is possible to cool the inside of the apparatus more efficiently.

In the embodiment of the present invention, the current value is observed in two levels using the comparator. However, the current value can be detected at the analog level, and the control of the cooling fan can be turned ON / OFF. It is needless to say that the same effect can be obtained not only by the control but also by performing the control of changing the rotation speed of the cooling fan in multiple stages.

[0025]

As described above, according to the present invention,
The control means has determined that the measured value of the current value measuring means has exceeded a predetermined value.
Then, after a predetermined time has elapsed, the driving of the cooling means is started.
Thus, the driving of the cooling means can be started at an optimum timing.

[0026]

[0027]

[0028]

[Brief description of the drawings]

FIG. 1 is a sectional view showing an image recording apparatus as a reference example .

FIG. 2 is a control block diagram showing a reference example of the present invention.

Figure 3 is a diagram showing the real施例of the present invention.

[Explanation of symbols]

 S Recording paper (sheet material) 7 Photosensitive drum 11 Fixing roller 13 Cooling fan (Cooling means) 18 Current detection resistor (Current value measuring means) 20 CPU 21 Image controller (Image signal forming unit)

Continuation of front page (56) References JP-A-5-204221 (JP, A) JP-A-5-201102 (JP, A) JP-A-6-91986 (JP, A) JP-A-5-107877 (JP) , A) JP-A-57-101861 (JP, A) JP-A-62-285264 (JP, A) JP-A-2-6977 (JP, A) Japanese Utility Model Application No. Sho 61-92954 (JP, U) Japanese Utility Model Application 3-86363 (JP, U) Japanese Utility Model Showa 60-100754 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21/00 370-540 G03G 21/14 B41J 2/44 B41J 29/377 G05D 23/19

Claims (1)

(57) [Claims] An image recording unit for recording an image on a sheet material in accordance with an image signal from the image signal forming unit; a cooling unit for cooling the inside of the apparatus main body ;
Current value measuring means for measuring a current value,
The drive of the cooling means is controlled by comparing the measured value of the stage with a predetermined value.
Control means for controlling the current value measured by the current value measurement means.
After a predetermined time has passed after exceeding the value, the cooling means is driven.
An image recording apparatus characterized in that the image recording is started .